A new study reveals that people who eat or drink more foods that contain antioxidant flavonols, which are found in many fruits and vegetables as well as tea, can experience a slower rate of memory decline, according to Neuroscience News.
Flavonols are a group of phytochemicals found in plant pigments that are known to have beneficial effects on health.
Tea is a source of flavonols
“Something as simple as eating more fruits and vegetables and drinking more tea can be an easy way to take an active role in maintaining brain health,” says researcher Thomas Holland, of Rush University Medical Center in Chicago.
Over the course of seven years, the study included 961 people, with an average age of 81, who did not have dementia. Participants filled out a questionnaire each year about how often they ate certain foods. Cognitive and annual memory tests were also completed, including recalling word lists and remembering numbers and putting them in the correct order.
Participants also answered for other factors, such as their level of education, the amount of time they spent doing physical activities, and the amount of time they spent doing mental activities such as reading and playing games.
The secret is in the flavonols
The subjects were divided into five equal groups based on the amount of flavonols they had in their diet. While the average intake of flavonols in adults in the United States is about 16 to 20 milligrams per day, the study population had an average dietary intake of total flavonols of about 10 milligrams per day.
The lowest group took about 5 mg per day and the highest group consumed an average of 15 mg per day. This is the equivalent of about 1 cup of dark leafy greens.
19 cognitive tests
To determine rates of cognitive decline, the researchers used a global cognitive score that summarizes 19 cognitive tests. The average score ranged from 0.5 for people without thinking problems, to 0.2 for people with mild cognitive impairment, to -0.5 for people with Alzheimer’s disease.
The researchers found that the cognitive score of people with the highest intake of flavonols was slower by an average of 0.4 units per decade compared to people with the lowest intake of flavonols.
Researcher Holland suggests that the reason may be due to the antioxidant and anti-inflammatory properties inherent in the compounds of the flavonol class, which in the framework of the study were divided into kaempferol, quercetin, myricetin and isorhamnetin.
Sources of flavonols
All four components of flavonols are present in the following foods and beverages in high proportions:
• Kaempferol in kale, beans, spinach and broccoli.
• Quercetin in tomatoes, turnips, apples and tea
• Myristin in tea, kale, tomato and orange
Isorhamnetin in pear, olive oil and tomato sauce.
And researcher Holland explains that the results of the study show an association between high amounts of dietary flavonols, especially kaempferol, and a slowdown in cognitive decline, but it does not prove that flavonols directly caused a slower rate of cognitive decline.